This invention relates to the field of devices making it possible to seal or protect measuring or monitoring systems from fraud. It relates very particularly to a means for tamperproofing of flowmeters.
Flowmeters, as, for example, water meters, comprise in the upper part of their cylindrical body--where the measuring means, including the counter, are introduced--a closing ring in the form of a threaded nut which is provided with a tamperproof system, generally of the security lead type, intended to monitor fraud.
Despite these precautions, the guarantees often prove inadequate and checks or meter readers are often brought to provide resetting interventions of sealing systems and of lock nuts which assure closing of meter housings.
The object of the invention is to mitigate these drawbacks. The invention proposes for this purpose a cap, with cover, for a flowmeter, intended not only to assure a sealing function against fraud but further making it possible, on the one hand, to assure a protective covering for the meter and, on the other hand, thanks to the design of its internal structure, to orient the reading face toward the user during a reading.
The new device according to the invention is of the cap type, and consists essentially of the combination of (a) a cylindrical skirt provided on the inside face of its upper edge with a series of recesses regularly spaced on the periphery and having hooks extending vertically, perpendicular to the skirt, to engage the shoulder of the standard threaded lock nut for the meter, (b) a ring with a vertical lip having outward projections extending into said recesses, and (c) a cover whose opening and closing hinge is pivoted in an opening made on the upper edge of the skirt.
The hooks are intended to assure a locking over the entire periphery of the threaded nut of the meter, while the ring serves to drive in rotation the meter counter thanks to its inside lip.
According to an important characteristic of the device, one of said hooks is made fragile at the level of the SIM (Service of Instruments and Measurements) check point which is provided on the head of said hook, at the level of the upper edge of the skirt. Thus, during a strong traction on the cover or on the closing ring, the pointed hook can break, which makes it possible to detect an attempted fraud, without thereby damaging the tamperproofing of the meter.
Other characteristics are seen from the following description, relating to a nonlimiting embodiment shown by the accompanying drawings which diagramatically represent: